(!!!!) (Recommended Pair) 12BH7A Sylvania NOS gray oval plates NOS 1965 era (8.2/8.4ma and 10/7.6ma)

1 low noise tube) 12BH7A Sylvania NOS gray oval plates NOS 1965 era same build 1 tube) 8.2/8.4ma Gm=2750/2900 red printing 1 tube) 10/7.6ma Gm=3100/2500 darker shade gray plate Low Noise and not microphonic Smooth sound, good detail and low noise   Recommended for - Octave M90 mono amps (http://www.octave.de/)- Quicksilver Audio V4 mono amp- Quicksilver Triode amp- Thor- Doshi Alaap preamp- Art Audio Diavolo- Vexo S40 amp- Art Audio Carissa Signature amp Art Audio PX25 amp- Universal Audio LA2A